ICSE Class 6 Chemistry - Introduction to Chemistry - Test 3 (Advanced)
1. Ice melts on a sunny day. What type of change is this?
A. Physical process
B. Chemical process
C. Biological process
2. Iron nails left in water turn reddish-brown. Why does this happen?
A. Physical deposition
B. Chemical reaction forming rust
C. Melting of iron
3. Why does water in a shallow pan evaporate faster than in a bottle?
A. Less air around the bottle
B. Because water is purer
C. Larger surface area allows faster evaporation
4. Dry ice disappears leaving no residue. What process is this?
A. Sublimation
B. Evaporation
C. Condensation
5. Sugar completely dissolves in water. This forms a:
A. Mixture with particles visible
B. Homogeneous solution
C. Heterogeneous mixture
6. Burning paper produces smoke and ash. This is a:
A. Physical change
B. Dissolving process
C. Chemical change
7. A piece of iron sinks in water. This is because:
A. Its density is higher than water
B. Water is too small in volume
C. Iron reacts with water
8. Air supports burning because it contains:
A. Only nitrogen
B. Oxygen
C. Carbon dioxide only
9. Why does puddle water vanish quickly after rain?
A. It freezes
B. It condenses
C. Evaporation due to larger surface area and heat
10. Sand can be removed from water by:
A. Filtration
B. Evaporation
C. Distillation
11. In a chemistry experiment, what is important?
A. Random mixing
B. Careful observation
C. Using only chemicals at home
12. Colour and melting point are examples of:
A. Physical properties
B. Chemical properties
C. Biological properties
13. Sugar in water is an example of a:
A. Heterogeneous mixture
B. Compound
C. Solution
14. Dry ice disappears without melting. This is called:
A. Sublimation
B. Evaporation
C. Condensation
15. Rusting of iron is an example of:
A. Physical change
B. Chemical change
C. Melting
16. Pure water can be obtained from seawater by:
A. Filtration
B. Sedimentation
C. Distillation
17. Oxygen gas is an example of:
A. Element
B. Compound
C. Mixture
18. Water (H₂O) is a:
A. Element
B. Compound
C. Mixture
19. Salt mixed with sand can be separated by:
A. Physical methods
B. Chemical reaction
C. Burning
20. How is salt recovered from seawater?
A. Filtration
B. Sedimentation
C. Evaporation